Scope of this technical record
Functional route from PWM command through isolation, gate driver, isolated supply, clamp/protection, IGBT/IPM module, current feedback and motor output.
Gate-driver and output-stage work is high-energy repair work. Do not energize a replacement module until driver and protection evidence is proven by qualified procedure.
Gate-driver / output-stage route
The driver route is checked before trusting another replacement module.
Gate-driver output-stage image
The driver path decides module survival
A good IGBT module can fail immediately if the driver cannot turn it on and off correctly, if an isolated supply is weak, if clamp components are damaged, or if current feedback fails to protect the device. This circuit path therefore sits behind overcurrent, short-circuit, output phase-loss and repeat-module-failure pages.
The route is intentionally evidence based: compare like channels, identify asymmetric damage, verify supply presence and document feedback/protection before another power-up.
Driver evidence table
The table is written for repair-intake decisions, not for live probing instructions.
Gate-driver and output-stage boundary
| Area | Failure effect | Evidence requested |
|---|---|---|
| Driver IC / optocoupler | Wrong or missing gate command | Channel comparison and visible damage |
| Isolated driver supply | Weak gate drive / overheating | Supply presence and capacitor condition |
| Gate resistor / clamp | Slow switching or overvoltage stress | Resistance and visible heat damage |
| Current feedback | False trip or no protection | Sensor/channel comparison |
| Motor cable | Destroys output module externally | Insulation and terminal evidence |
Field record checklist
- Fault timing
- Original and replacement module history
- Driver-board photos
- Isolated supply evidence
- Current sensor evidence
- Motor/cable boundary evidence
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Board-area record for driver repair boundary.
Turn this record into a qualified service request
A repair decision is much more reliable when the request includes the exact identity of the drive, the first fault evidence and the machine condition when the symptom appeared.
- Complete drive type code / MLFB or nameplate model
- Fault code, fault value and first event before reset
- When the event appears: power-up, enable, ramp, run, decel or stop
- Motor/cable connected or isolated during the symptom
- Visible board, option-card, module and connector identifiers
- Previous repair history, replacement parts and repeat-failure pattern